Modeling of vacuum pulse carburizing of steel

Zajusz, Marek; Tkacz–Śmiech, Katarzyna; Danielewski, Marek

doi:10.1016/j.surfcoat.2014.08.023

Cited by 36 publications

(11 citation statements)

References 35 publications

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“…Vacuum carburization, as a surface strengthening method, plays an important role in the process of obtaining excellent comprehensive mechanical properties of 20Cr2Ni4A alloy steel. Vacuum carburization is a rapid process in which acetylene is injected into a high-temperature furnace in pulsed mode under low pressure and vacuum [6,7,8]. However, vacuum carburizing still has its disadvantages, such as a high carburizing temperature, a long carburizing cycle, an uneven structure, and coarse carbide particles.…”

Section: Introductionmentioning

confidence: 99%

Study of the Catalytic Strengthening of a Vacuum Carburized Layer on Alloy Steel by Rare Earth Pre-Implantation

Cai-yun

Xing³

et al. 2019

Materials

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Conventional carburizing has disadvantages, such as high energy consumption, large deformation of parts, and an imperfect structure of the carburizing layer. Hence, a rare earth ion pre-implantation method was used to catalyze and strengthen the carburized layer of 20Cr2Ni4A alloy steel. In this study, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive microanalysis (EDS), transmission electron microscopy (TEM), and Rockwell/Vickers hardness testing were used to analyze the microstructure, phase composition, retained austenite content, hardness, carburized layer thickness, and carbon diffusion. The results showed that lanthanum and yttrium ions implanted into the 20Cr2Ni4A steel formed solid solutions of rare earth ions and a large number of dislocations, which improved the diffusion coefficient of carbon elements on the carburized surface and the uniformity of the carbon distribution. Simultaneously, rare earth ion implantation improved the structure and hardness of the vacuum carburized layer. Compared to the lanthanum ion implantation, yttrium ion implantation caused the structure of the carburized layer to be finer, and the carbon diffusion coefficient increased by 1.17 times; in addition, the surface hardness of the carburized layer was 61.8 HRC.

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Section: Introductionmentioning

confidence: 99%

Study of the Catalytic Strengthening of a Vacuum Carburized Layer on Alloy Steel by Rare Earth Pre-Implantation

Cai-yun

Xing³

et al. 2019

Materials

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“…In subsequent diffusion stage, the carbon atoms diffuse from the surface into the core, hence the decrease in surface carbon content. For LPC of low alloy steel, such as C20 steel carburized at 920 • C, by adjusting the LPC process parameters, the surface maximum carbon content reached about 1.3 wt.% in each boost stage and dropped to 0.9 wt.% at the end of each diffusion stage [13]. However, for carburizing 14Cr14Co13Mo4 steel, as shown in Figure 8a, the steel surface carbon content quickly reached a maximum value of about 4.08 wt.%.…”

Section: Discussionmentioning

confidence: 99%

Pre-Coated Fe–Ni Film to Promote Low-Pressure Carburizing of 14Cr14Co13Mo4 Steel

Yin

Wang

et al. 2019

Coatings

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Case-hardening 14Cr14Co13Mo4 martensitic stainless steel needs to be carburized to improve surface performance. Low-pressure carburization has the benefit of having oxidation-free production and being ecofriendly. However, compared with the low-pressure carburization of the low-alloy steel, low-pressure carburization of the 14Cr14Co13Mo4 steel consumes more time and has a risk of network carbides. In order to promote carbon diffusion and avoid network carbide, Fe–Ni films with various thickness were electrodeposited on the 14Cr14Co13Mo4 steel prior to low-pressure carburization. The experimental results show that, under the same carburizing conditions, the surface carbon content decreases and the carburized layer increases with the increase of Fe–Ni film thickness. After the hardening heat treatment, the effective case depth (ECD) of the sample coated with 6.0 μm Fe–Ni film was increased by 29% compared to that of the uncoated sample. The morphology of carbides was a strip-shaped, discontinuous network distribution in the uncoated sample, while in the Fe–Ni coated samples, the carbides changed to a globular, uniformly dispersed distribution. The effect of Fe–Ni film on the low-pressure carburizing of steel is explained by the simulation of the carbon diffusion using DICTRA software. The Fe–Ni films reduce the steel surface carbon content in each boost stage of low-pressure carburizing and release carbon atoms in every diffusion stage. Through this adjustment mechanism, the steel surface carbon content can be reduced and carburized layer growth can be promoted.

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“…This model carries the Darken Bi-velocity that consists of diffusion and drift velocities. This Bi-velocity is applied to carburizing process, which model the carburizing process further [28]. This process evaluates the kinetics of Carbon transfer to the solid surface at variable conditions, which is significant for carburizing process.…”

Section: Vacum Pulse Carburizingmentioning

confidence: 99%

Study on Upgradation in Carburizing Technologies for steel strength

Nasar

Ullah

Suri

2019

Journal of Applied and Emerging Sciences

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Carburizing technologies are used to provide strength on low quality metals. This technology is being developing with novel improvements significantly. The carburizing process consists of, first releasing Carbon monooxide from charcoal material and then transfers carbon to raw metal. There are favorable upgradation in these technologies from researchers which have a paramount industrial importance. In Vacuum gas carburizing, the steel metal is carburized with (Acetylene and Propane) gases. These gases are at low pressure and high temperature. The results show that the metal is 1.5 times harder than its raw form. There are also used mathematical models to validate the results. It used gas and solid phases for validation. In pulse carburizing, carbon diffusion on steel is investigated with heat treatment. This process includes several carburizing stages. This process is based on Darken bi velocity and drift velocity. It accounts to demonstrate the kinetics of carbon transfer on steel surface. This design is very useful by regarding carburizing time for this process design. In Plasma carburizing, the mixtures of gases are used to harden the steel. The carburizing temperature was varied in cementite and martensitic. The favorable results show that these specimens have (Lower surface roughness, higher surface hardness and Low wear rate). It is a most novel diffusion controlled novel process till the present time. The carburized metal is used in industry by including (Turbine gears and Air craft engine). Henceforth, It is of great importance to study the carburizing technologies for providing better strength on metal.

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Modeling of vacuum pulse carburizing of steel

Cited by 36 publications

References 35 publications

Study of the Catalytic Strengthening of a Vacuum Carburized Layer on Alloy Steel by Rare Earth Pre-Implantation

Study of the Catalytic Strengthening of a Vacuum Carburized Layer on Alloy Steel by Rare Earth Pre-Implantation

Pre-Coated Fe–Ni Film to Promote Low-Pressure Carburizing of 14Cr14Co13Mo4 Steel

Study on Upgradation in Carburizing Technologies for steel strength

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